1. Field of the Invention
The invention relates to integrated circuits for use at microwave and millimeter wave frequencies, and more particularly to voltage controlled analog phase shifters of MMIC design
2. Prior Art
There is a need in microwave and millimeter wave electronically steered, phased array antennas for a voltage controlled phase shifter. In such systems, the antenna beam can be steered in azimuth and/or elevation by altering the phase of the excitation of each radiating element.
There are many known networks that can be employed for phase shifting applications at microwave and millimeter wave frequencies. Networks of the common classes have been reviewed in an article by R. V. Garver entitled "Broad Band Diode Phase Shifters", IEEE Transistors Vol. MTT 20, No. 5, May 1972. These include loaded lines, hybrid coupled reflection networks, switched lines and lumped element networks (high pass/low pass). Applications exist for both digital and analog phase shifters, the latter being favored when adaptive control of the beam is sought.
The realizations of known circuits in monolithic microwave embodiments have tended to require excessive chip area and excessive power consumption.